Peel and quarter the onion. Peel, wash and cut 1 carrot into pieces. Put both in a large pot with approx. 2 1/2 l cold water, 1 heaped tsp. salt, bay leaf and peppercorns. Rinse the meat and put it inside.
Bring everything to the boil and skim off the foam more often. Cover and simmer for 2 1/2 hours.
While the meat is boiling, peel and wash the beetroot and 2 carrots. Cut carrots into sticks and beetroot into cubes. Dice the bacon. Remove the meat from the broth and sieve the broth.
Fry the bacon in a large pan until crispy. Add beetroot and cover.
Steam for about 10 minutes. Stir in tomato paste, 1 tablespoon sugar and 2 tablespoons vinegar and continue to steam briefly. Pour in approx. 100 ml stock. Add the carrots and continue cooking covered for about 15 minutes.
Drain the sauerkraut. Peel and wash the potatoes and cut them into thick sticks. Bring the rest of the meat stock to the boil, cover and cook the potatoes for about 15 minutes. Dice the meat. Add beetroot mixture and sauerkraut to the stock and cook for another 5 minutes.
Wash the chives and cut into small rolls. Finally, season the stew with salt, pepper and vinegar. The borscht I arrange with the sour cream and the chives.